wt.c

早期freebsd实现

case 0:
cmds(0x28);
break;
case 1:
cmds(0x29);
break;
case 2:
cmds(0x27);
break;
case 3:
cmds(0x24);
	}
	return(0);
}

/*
 * close routine
 * called on last device close
 * If not rewind-on-close, leave read or write command intact.
 */
wtclose(dev)
{
	int wtdsl2();

#ifdef DEBUG
	debug("WTclose:\n");
#endif
	if (Hogproc == myproc)
		Hogproc = (struct proc *) 0;
	if (!exflag && (wtflags & TPWANY) && !(wtflags & (TPSESS|TPDEAD))) {
		if (!(wtflags & TPWO))
			wstart();
#ifdef DEBUG
		debug("WT: Writing file mark\n");
#endif
		wmark();	/* write file mark */
#ifdef DEBUG
		debug("WT: Wrote file mark, going to wait\n");
#endif
		if (rdyexc(HZ/10) == ERROR) {
			wtsense(0);
			}
		}
	if (TP_REWCLOSE(dev) || (wtflags & (TPSESS|TPDEAD))) {
	/* rewind tape to beginning of tape, deselect tape, and make a note */
	/* don't wait until rewind, though */
		/* Ending read or write causes rewind to happen, if no error,
		 * and READY and EXCEPTION stay up until it finishes */
		if (wtflags & (TPRO|TPWO))
		{
#ifdef DEBUG
			debug("End read or write\n");
#endif
			rdyexc(HZ/10);
			ioend();
			wtflags &= ~(TPRO|TPWO);
		}
		else	wtwind();
		wtflags |= TPSTART | TPREW;
		timeout(wtdsl2, 0, HZ);
	}
	else if (!(wtflags & (TPVOL|TPWANY)))
	{
		/* space forward to after next file mark no writing done */
		/* This allows skipping data without reading it.*/
#ifdef DEBUG
		debug("Reading past file mark\n");
#endif
		if (!(wtflags & TPRO))
			rstart();
		rmark();
		if (rdyexc(HZ/10))
		{
			wtsense(TP_WRP);
		}
	}
	wtflags &= TPREW|TPDEAD|TPSTART|TPRO|TPWO;
	return(0);
}

/* return ERROR if user I/O request should receive an I/O error code */

wtsense(ignor)
{
	wtflags &= ~(TPRO|TPWO);
#ifdef DEBUGx
	debug("WTsense: start ");
#endif
	if (rdstatus(&wterror) == ERROR)
	{
#ifdef DEBUG
		debug("WTsense: Can't read status\n");
#endif
		return(ERROR);
	}
#ifdef DEBUG
	if (wterror.wt_err & (TP_ST0|TP_ST1))
	{
		debug("Tperror: status %x error %d underruns %d\n",
			wterror.wt_err, wterror.wt_ercnt, wterror.wt_urcnt);
	}
	else
		debug("done. no error\n");
#endif
	wterror.wt_err &= ~ignor;	/* ignore certain errors */
	reperr(wterror.wt_err);
	if (((wterror.wt_err & TP_ST0) && (wterror.wt_err & TP_ERR0)) ||
		    ((wterror.wt_err & TP_ST1) && (wterror.wt_err & TP_ERR1)))
			return	ERROR;

	return SUCCESS;
}

/* lifted from tdriver.c from Wangtek */
reperr(srb0)
int srb0;
{
	int s0 = srb0 & (TP_ERR0|TP_ERR1);	/* find out which exception to report */
 
	if (s0) {
		if (s0 & TP_USL) 
			sterr("Drive not online");
		else if (s0 & TP_CNI) 
			sterr("No cartridge");
		else if ((s0 & TP_WRP) && !(wtflags & TPWP))
		{
			sterr("Tape is write protected");
			wtflags |= TPWP;
		}
		/*
		if (s0 & TP_FIL)
			sterr("Filemark detected");
		*/
		else if (s0 & TP_BNL)
			sterr("Block in error not located");
		else if (s0 & TP_UDA)
			sterr("Unrecoverable data error");
		/*
		else if (s0 & TP_EOM)
			sterr("End of tape");
		*/
		else if (s0 & TP_NDT)
			sterr("No data detected");
		/*
		if (s0 & TP_POR)
			sterr("Reset occured");
		*/
		else if (s0 & TP_BOM)
			sterr("Beginning of tape");
		else if (s0 & TP_ILL)
			sterr("Illegal command");
	}
}
	
sterr(errstr)
char	*errstr;
{
	printf("Streamer: %s\n", errstr);
}

/* Wait until rewind finishes, and deselect drive */
wtdsl2() {
	int	stat;

	stat = inb(wtport) & (READY|EXCEP);
#ifdef DEBUG
	debug("Timeout: Waiting for rewind to finish: stat %x\n", stat);
#endif
	switch (stat) {
		/* They're active low, ya'know */
		case READY|EXCEP:
			timeout(wtdsl2, (caddr_t) 0, HZ);
			return;
		case EXCEP: 
			wtflags &= ~TPREW;
			return;
		case READY:
		case	0:
			wtflags &= ~TPREW;
			sterr("Rewind failed");
			wtsense(TP_WRP);
			return;
			}
	}

wtwind() {
#ifdef DEBUG
	debug("WT: About to rewind\n");
#endif
	rwind();	/* actually start rewind */
}

wtintr(unit) {
	if (wtflags & (TPWO|TPRO))
	{
		isrlock = 1;
		if (wtio) isr();
		isrlock = 0;
	}
}

wtinit() {
	if (wtchan < 1 || wtchan > 3)
	{
		sterr("Bad DMA channel, cannot init driver");
		return;
	}
	wtlinit();	/* init assembly language variables */
	pageset();
}

rdyexc(ticks)
{
	int s;
#ifdef DEBUG
	int os = 0xffff;		/* force printout first time */
#endif
	for (;;) {			/* loop until ready or exception */
		s=(inb(wtport) & 0xff);	/* read the status register */
#ifdef DEBUG
		if (os != s) {
			debug("Status reg = %x\n", s); /* */
			os = s;
			}
#endif
		if (!(s & EXCEP))	/* check if exception have occured */
			break;
		if (!(s & READY))	/* check if controller is ready */
			break;
		s = splbio();
		delay((ticks/HZ)*1000000); /* */
		splx(s);
	}
#ifdef DEBUG
	debug("Status reg = %x on return\n", s); /* */
#endif
	return((s & EXCEP)?SUCCESS:ERROR);  /* return exception if it occured */
}

pollrdy()
{
	int	 sps;
#ifdef DEBUG
	debug("Pollrdy\n");
#endif
	sps = splbio();
	while (wtio) {
		int error;

		if (error = tsleep((caddr_t)&wci, WTPRI | PCATCH,
			"wtpoll", 0)) {
			splx(sps);
			return(error);
		}
	}
	splx(sps);
#ifdef DEBUG
	debug("Finish poll, wci %d exflag %d\n", wci, exflag);
#endif
	return (EIO);
}

wtdma()		/* start up i/o operation, called from dma() in wtlib1.s */
{
	wtio = 1;
	if (!wtimeron)
	{
		wtimeron = 1;
		timeout(wtimer, (caddr_t) 0, HZ/2);
	}
}

wtwake()	/* end i/o operation, called from isr() in wtlib1.s */
{
	wtio = 0;
	wakeup(&wci);
}

pageset()
{
	unsigned long pp;

	pp = (unsigned long) pagebuf;
	pageaddr = kvtop(pp);
#ifdef DEBUG
	debug("pageset: addr %lx\n", pageaddr);
#endif
}



#define near

static near
sendcmd()
{
	/* desired command in global mbits */

	outb(CTLPORT, mbits | REQUEST);		/* set request */
	while (inb(STATPORT) & READY);		/* wait for ready */
	outb(CTLPORT, mbits & ~REQUEST);	/* reset request */
	while ((inb(STATPORT) & READY) == 0);	/* wait for not ready */
}

static near		/* execute command */
cmds(cmd)
{
	register s;

	do s = inb(STATPORT);
	while ((s & STAT) == STAT);	/* wait for ready */

	if ((s & EXCEP) == 0)		/* if exception */
		return ERROR;		/* error */
	
	outb(CMDPORT, cmd);		/* output the command	*/

	outb(CTLPORT, mbits=ONLINE);	/* set & send ONLINE	*/
	sendcmd();

	return SUCCESS;
}

qicmd(cmd)
{
	return cmds(cmd);
}

rstart()
{
	return cmds(RDDATA);
}

rmark()
{
	return cmds(READFM);
}

wstart()
{
	return cmds(WRTDATA);
}

ioend()
{
	register s;
	register rval = SUCCESS;

	do s = inb(STATPORT);
	while ((s & STAT) == STAT);	/* wait for ready */

	if ((s & EXCEP) == 0)		/* if exception */
		rval = ERROR;		/* error */
	
	mbits &= ~ONLINE;
	outb(CTLPORT, mbits);		/* reset ONLINE */
	outb(MASKREG, wtchan+4);	/* turn off dma */
	outb(CLEARFF, 0);		/* reset direction flag */

	return rval;
}

wmark()
{
	register s;

	if (cmds(WRITEFM) == ERROR)
		return ERROR;

	do s = inb(STATPORT);
	while ((s & STAT) == STAT);	/* wait for ready */

	if ((s & EXCEP) == 0)		/* if exception */
		return ERROR;		/* error */

	return SUCCESS;
}

rwind()
{
	register s;

	mbits = CMDOFF;

	do s = inb(STATPORT);
	while ((s & STAT) == STAT);	/* wait for ready */

	outb(CMDPORT, REWIND);
	sendcmd();

	return SUCCESS;
}

rdstatus(stp)
char *stp;		/* pointer to 6 byte buffer */
{
	register s;
	int n;

	do s = inb(STATPORT);
	while ((s & STAT) == STAT);	/* wait for ready or exception */

	outb(CMDPORT, RDSTAT);
	sendcmd();			/* send read status command */

	for (n=0; n<6; n++)
	{
#ifdef DEBUGx
		debug("rdstatus: waiting, byte %d\n", n);
#endif
		do s = inb(STATPORT);
		while ((s & STAT) == STAT);	/* wait for ready */
#ifdef DEBUGx
		debug("rdstatus: done\n");
#endif
		if ((s & EXCEP) == 0)		/* if exception */
			return ERROR;		/* error */

		*stp++ = inb(DATAPORT);		/* read status byte */

		outb(CTLPORT, mbits | REQUEST);	/* set request */
#ifdef DEBUGx
		debug("rdstatus: waiting after request, byte %d\n", n);
#endif
		while ((inb(STATPORT)&READY) == 0);	/* wait for not ready */
		for (s=100; s>0; s--);		/* wait an additional time */

		outb(CTLPORT, mbits & ~REQUEST);/* unset request */
#ifdef DEBUGx
		debug("rdstatus: done\n");
#endif
	}
	return SUCCESS;
}

t_reset()
{
	register i;
	mbits |= RESET;
	outb(CTLPORT, mbits);		/* send reset */
	delay(20);
	mbits &= ~RESET;
	outb(CTLPORT, mbits);		/* turn off reset */
	if ((inb(STATPORT) & RESETMASK) == RESETVAL)
		return SUCCESS;
	return ERROR;
}

static
dma()
{
	int x=splbio();
	wtdma();
	outb(CLEARFF, 0);
	outb(MODEREG, mode);	/* set dma mode */
	outb(dmareg, bufptr & 0xFF);
	outb(dmareg, (bufptr>>8) & 0xFF);
	outb(pagereg, (bufptr>>16) & 0xFF);                         
	outb(dmareg+1, (BLKSIZE-1) & 0xFF);
	outb(dmareg+1, (BLKSIZE-1) >> 8);
	outb(wtport, eqdma+ONLINE);
	outb(MASKREG, wtchan);	/* enable command to 8237, start dma */
	splx(x);
}

static near
wtstart(buf, cnt)
long buf;
int cnt;
{
	register s;

	bufptr = buf;		/* init statics */
	numbytes = cnt;
	wci = 0;		/* init flags */
	exflag = 0;
	bytes = 0;		/* init counter */

	do s = inb(STATPORT) & STAT;
	while (s == STAT);	/* wait for ready or error */

	if (s & EXCEP)		/* no error */
	{
		dma();
		return SUCCESS;
	}
	return ERROR;		/* error */
}

rtape(buf, cnt)
long buf;			/* physical address */
int cnt;			/* number of bytes */
{
	mode = dma_read;
	return wtstart(buf,cnt);
}

wtape(buf, cnt)
long buf;			/* physical address */
int cnt;			/* number of bytes */
{
	mode = dma_write;
	return wtstart(buf,cnt);
}

isr()
{
	int stat = inb(wtport);
	if (!(stat & EXCEP))	/* exception during I/O */
	{
		if (bytes + BLKSIZE >= numbytes) wci = 1;
		exflag = 1;
		goto isrwake;
	}
	if ((stat & READY) || !(inb(STATUSREG) & dma_done))
		return;
	exflag = 0;
	outb(wtport, ONLINE);
	bytes += BLKSIZE;
	if (bytes >= numbytes)	/* normal completion of I/O */
	{
		wci = 1;
isrwake:
		outb(MASKREG, 4+wtchan);	/* turn off dma */
		wtwake();			/* wake up user level */
	}
	else
	{			/* continue I/O */
		bufptr += BLKSIZE;
		dma();
	}
}

wtlinit()
{
	switch (wtchan) {
	case 1:
		return;
	case 2:
		pagereg = 0x81;
		dma_done = 4;
		break;
	case 3:
		eqdma = 0x10;
		pagereg = 0x82;
		dma_done = 8;
		break;
	}
	dma_write = wtchan+0x48;
	dma_read = wtchan+0x44;
	dmareg = wtchan+wtchan;
}

/*
 * delay i microseconds
 */
delay(i)
register int i;
{
	while (i-- > 0)
		DELAY(1000);
}

wtsize()
{
}

wtdump()
{
}

#include <i386/isa/isa_device.h>
#include <i386/isa/icu.h>

int	wtprobe(), wtattach();
struct	isa_driver wtdriver = {
	wtprobe, wtattach, "wt",
};

wtprobe(dvp)
	struct isa_device *dvp;
{
	int val,i,s;

#ifdef lint
	wtintr(0);
#endif

	wtport = dvp->id_iobase;
	if(t_reset() != SUCCESS) return(0);
	return(1);
}

wtattach() { }

#endif NWT